The present invention relates to a vehicle with movable spoilers.
As is known, many high-performance vehicles have spoilers appropriately located on the vehicle body to increase the vertical load on the vehicle in movement and so improve road-holding and traction.
Spoilers, however, have the major drawback of impairing the aerodynamic efficiency of the vehicle, so that considerably more power is required to achieve and maintain a given vehicle speed.
By way of a solution to the problem, some vehicle manufacturers have equipped certain models with spoilers which are movable selectively, on command, to assume a rest or minimum-angle position in which the aerodynamic efficiency of the vehicle is affected as little as possible, or an extracted or maximum-angle position to increase the vertical load on the vehicle in movement and so improve road-holding and traction. The switch from the minimum- to maximum-angle position is made when the vehicle exceeds a predetermined threshold speed.
In recent years, the need to reduce pollutant emissions and reduce fuel consumption has induced manufacturers to perfect the movable-spoiler solution by enabling spoilers to be set to any position between the minimum- and maximum-angle positions, thus enabling spoiler position control as a function of vehicle speed. That is, the spoiler angle can be increased in proportion to vehicle speed so as to gradually increase the vertical load on the vehicle as speed increases.
Though excellent in terms of fuel consumption, particularly at low speed, the above solution seriously complicates high-speed performance of the vehicle.
Firstly, as speed increases, the vehicle tends to sink dangerously close to the road surface.
Secondly, as speed increases, the vertical load on the vehicle gradually compresses and distorts the suspensions, thus making the vehicle harder to drive. More specifically, the vertical load on the vehicle affects certain characteristics of the suspensions, such as travel and camber angle, thus resulting in a radical change in vehicle performance in the presence of attitude variations caused when driving over rough road surfaces. Which change can only be partly counteracted by adopting extremely complex, high-cost suspension design solutions.
While improving road-holding and traction, the gradual increase in vertical load also makes steering harder, thus impairing driving comfort at high speed.
It is therefore an object of the present invention to provide a vehicle with movable spoilers, designed to eliminate the aforementioned drawbacks.
According to the present invention, there is provided a vehicle with movable spoilers, the vehicle having at least one spoiler movable between a minimum-angle position producing a minimum increase in vertical load, and a maximum-angle position producing a maximum increase in vertical load; and spoiler actuating means for adjusting the position of the spoiler between said minimum-angle position and said maximum-angle position as a function of the speed of the vehicle; the vehicle being characterized in that the spoiler actuating means provide, up to a given maximum speed, for adjusting the position of the spoiler to increase the vertical load as speed increases, and for maintaining the vertical load at a substantially constant given value as long as the speed of the vehicle exceeds said maximum speed.